Management of pseudoaneurysm of the leg: is Color Doppler US enough?

The authors describe two clinical cases showing that Color Doppler Ultrasonography (US) examination is effective and sufficient in the presence of a clinical suspicion of pseudoaneurysm. In cases of iatrogenic damage and post-traumatic lesions, US provides an easy and accurate diagnosis depicting the location and the morphology of the false aneurysm. The patient can thus be referred to appropriate treatment without undergoing further diagnostic examinations. Moreover, regardless of the performed treatment, Color Doppler US is an efficient non-invasive diagnostic tool in the follow-up.

Cardiovascular phenotype of young adults and angiotensinogen alleles.

OBJECTIVES AND DESIGN: Angiotensinogen (AGT) gene variants influence angiotensinogen plasma levels in children and young adults. The angiotensinogen promoter (-6)A variant facilitates gene transcription in human tissues and it has been associated with high blood pressure in older adults. A young adult population can be used as a model to study genotype/phenotype associations between AGT (-6) variants and cardiovascular variables. METHODS AND RESULTS: Anthropometric measurements, blood pressure and heart rate were taken in 422 white Caucasian students (mean age 23.5 years, SD 2.5 years). Family history for hypertension, physical activity and smoking history were evaluated. Left ventricular variables were measured by echocardiography. Carotid artery wall intimal-media thickness (IMT) was measured by high resolution sonography and digitalized morphometry. The AGT G(-6)A alleles were evaluated by mutagenically separated polymerase chain reaction controlled by direct sequencing. No significant associations were found between angiotensinogen genotype and blood pressure, cardiac variables [except for deceleration time in females which increased with the number of (-6)A alleles] and IMT. Allele frequencies were similar between the first and third tertile of blood pressure and left ventricular mass, and were also similar between negative or positive family history for hypertension (the last group having significantly higher systolic blood pressure in males, P = 0.04 and diastolic blood pressure in females, P < 0.01). Moreover, no relevant interaction on the cardiovascular variables was found between AGT genotype and body mass index. CONCLUSIONS: The angiotensinogen G(-6)A variants do not affect cardiovascular parameters in young adults, but an effect of this polymorphism on cardiovascular phenotype (and hypertension) in older adults cannot be excluded. Additional factors, associated with ageing, should be present to unleash the supposed unfavourable potential of the (-6)A angiotensinogen variant.

A novel promoter variant of the natriuretic peptide clearance receptor gene is associated with lower atrial natriuretic peptide and higher blood pressure in obese hypertensives.

OBJECTIVE AND DESIGN: The clearance receptor for natriuretic peptides (NPRC), a candidate gene for essential hypertension, is highly expressed in adipose tissue, where is nutritionally regulated. The objectives of the present study were to sequence the human 5'-flanking regulatory region of NPRC, to identify allelic variants and their frequencies, and to study the genotype/phenotype correlation in hypertensive patients. METHODS AND RESULTS: Using polymerase chain reaction (PCR) and direct automated sequencing, a biallelic (A/C) polymorphism was detected at position -55 in a conserved promoter element named P1. The novel C(-55) variant makes the promoter sequence identical to the mouse gene and introduces a second Hgal site in the amplified DNA, allowing the genotyping of a large number of subjects. In a random sample of 232 white Caucasians the C(-55) allele was more commonly found (81.7% of all alleles) with 155 CC (66.8%), 69 AC (29.7%) and only eight AA (3.5%) genotypes. Atrial natriuretic peptide (ANP) levels were determined in 84 patients with essential hypertension. In the presence of obesity (body mass index (BMI) > or = 30 kg/m2) the homozygous CC hypertensives (n = 21) had significantly lower plasma ANP (33.6 +/- 11.1 pg/ml) compared with the AC patients (n = 11; 46.8 +/- 15.9 pg/ml; P = 0.01), whereas systolic blood pressure (SBP) and mean blood pressure (MBP) had the opposite association (SBP 163.9 +/- 18.7 versus 150.9 +/- 12.9 and MBP 123.3 +/- 12 versus 114.5 +/- 5.9 mmHg; P< 0.05). The difference in ANP levels were also present when overweight patients (BMI > or = 27 kg/m2) were considered. CONCLUSION: A common 'ancestral' C(-55) variant of the NPRC P1 promoter is associated with lower ANP levels and higher SBP and MBP in obese hypertensives. The C(-55) variant, in the presence of increased adiposity, might reduce plasma ANP through increased NPRC-mediated ANP clearance, contributing to higher blood pressure.

Low calorie diet enhances renal, hemodynamic, and humoral effects of exogenous atrial natriuretic peptide in obese hypertensives.

The expression of the natriuretic peptide clearance receptor is abundant in human and rat adipose tissue, where it is specifically inhibited by fasting. In obese hypertensives, plasma atrial natriuretic peptide (ANP) levels were found to be lower than in obese normotensives. Therefore, the increased adipose mass might influence ANP levels and/or its biological activity. The aim of the present study was to evaluate whether the humoral, hemodynamic, and renal effects of exogenous ANP in obese hypertensives might be enhanced by a very low calorie diet. Eight obese hypertensives received a bolus injection of ANP (0.6 mg/kg) after 2 weeks of a normal calorie/normal sodium diet, and blood pressure (BP), heart rate, ANP, cGMP, plasma renin activity, and aldosterone were evaluated for 2 hours before and after the injection. Diuresis and natriuresis were measured every 30 minutes. The patients then started a low calorie/normal sodium diet (510 kcal/150 mmol/d) for 4 days, and then the ANP injection protocol was repeated. The low calorie diet induced a slight weight loss (from 90.6+/-1.1 to 87. 7+/-1.2 kg; P<0.01), which was accompanied by increase of cGMP excretion (from 146.0+/-10.1 to 154.5+/-9.5 nmol/24 h; P<0.05) together with a reduction of BP (P<0.01 versus basal levels). ANP injection after diet was followed by an increase of ANP levels similar to that observed before diet, but plasma cGMP, diuresis, and natriuresis increased significantly only after diet. Similarly, the decrease of BP after ANP administration was significantly higher after diet (change in mean arterial pressure, -6.4+/-0.7 versus -4. 0+/-0.6 mm Hg; P<0.05) as well as that of aldosterone (P<0.01). These data show that a low calorie diet enhances the humoral, renal, and hemodynamic effects of ANP in obese hypertensives and confirm the importance of caloric intake in modulating the biological activity of ANP, suggesting that the natriuretic peptide system can play a role in the acute changes of natriuresis and diuresis associated with caloric restriction.

Plasma atrial natriuretic peptide and natriuretic peptide receptor gene expression in adipose tissue of normotensive and hypertensive obese patients.

OBJECTIVE: Human and rat adipose tissue contain very high levels of natriuretic peptides clearance receptor messenger (m)RNA, and fasting inhibits its gene expression in adipose tissue. In this study we evaluated plasma atrial natriuretic peptide (ANP) and gene expression of biologically active type A natriuretic peptide receptor (NPr-A) and clearance natriuretic peptide receptor (NPr-C) in adipose tissue of obese hypertensive and obese normotensive patients. DESIGN AND METHODS: We studied 27 untreated obese hypertensives, 26 obese normotensives (body mass index > or = 30 kg/m2), 24 non-obese essential hypertensives and 23 lean healthy subjects (body mass index < or = 25 kg/m2). Blood samples were withdrawn for ANP, plasma renin activity and aldosterone radioimmunoassays. Subcutaneous peri-umbilical adipose tissue samples were obtained, by needle aspiration, in 13 obese hypertensives and in 12 obese normotensives and used for RNA extraction. Then, complementary synthesis and semiquantitative polymerase chain reaction (PCR) with primers complementary to sequences of different exons of the genes encoding for NPr-A, NPr-C and beta-actin, were performed. 32P-labeled PCR products were separated by electrophoresis, blotted onto nylon membranes, and the exposed autoradiographic films were analysed by densitometry. NPr signals were normalized by the beta-actin expression level. RESULTS: Plasma ANP was lower in obese hypertensives than in obese normotensives (37.5+/-7 versus 43.2+/-6 pg/ml, P< 0.05), but was higher in non-obese hypertensives than in non-obese normotensives. In contrast, plasma renin activity and aldosterone were higher in the obese hypertensives. Although NPr-A and NPr-C expression were not statistically different between the two obese groups, the NPr-A: NPr-C mRNA ratios were significantly lower in obese hypertensives (P < 0.03). CONCLUSIONS: Our data suggest that in obese hypertensives compared to obese normotensives, the lower NPr-A: NPr-C ratio might determine decreased biological activity and/or an increased clearance of natriuretic peptide in adipose tissue, suggesting that the natriuretic peptide and its receptor system may be important in obesity-related hypertension where ANP levels are lower.